Further, due to the wide differences in the distribution of HLA alleles across different populations in different geographical areas, the associations between TNF-α polymorphisms including TNF-α-308G/A SNP and various pathological conditions including cancer shows a considerable variation which makes it important to evaluate and provide a direct functional link of any polymorphism with the disease or condition under study so as to nullify the possibility of observed association or disassociation due to the existence of linkage disequilibrium with the actual causative gene. The gene discussed is TNF; the disease is cancer.